Thin film of amorphous alloy

ABSTRACT

A thin film of an amorphous alloy comprising (i) at least one element selected from Fe and Co, (ii) at least one element selected from Pt and Pd and (iii) at least one element selected from (a) 3d transition elements other than Fe and Co, (b) 4d transition elements other than Pd, (c) 5d transition elements other than Pt, (d) light rare earth elements, (e) Group III B elements, (f) Group IV B elements, (g) Group V B elements, and (h) Group VI B elements, and the film having an easy axis of magnetization perpendicular to the film face. The thin film has excellent magnetooptical characteristics including increased coercive force and large Kerr-rotation angle and Faraday-rotation angle, and is excellent in resistance to oxidation and in consequence the coercive force and Kerr-angle of the film do not substantially change with time. The film has a high reflectance as well.

FIELD OF THE INVENTION

The present invention relates to a thin film of an amorphous alloyhaving excellent resistance to oxidation. More particularly, it relatesto a thin film of an amorphous alloy which has an easy axis ofmagnetization perpendicular to the film face and which is excellent inresistance to oxidation.

BACKGROUND OF THE INVENTION

It is known that thin films of an amorphous alloy j comprising at leastone transition metal such as iron and cobalt and at least one rare earthelement such as terbium (Tb) and gadolinium (Gb) have an easy axis ofmagnetization perpendicular to the film face and are capable of forminga small inverse magnetic domain with magnetization anti-parallel to themagnetization of the film. By corresponding the existence ornon-existence of this inverse magnetic domain to "1" or "37 0", itbecomes possible to record a digital signal on the amorphous alloy thinfilm as mentioned above.

As thin films of an amorphous alloy comprising at least one transitionmetal and at least one rare earth element which can be used asmagnetooptical recording media, thin films of amorphous alloys of Tb-Feseries containing from 15 to 30 atom % of Tb, are disclosed, forexample, in Japanese Patent Publication 57-20691. There are also knownmagnetooptical recording media comprising a thin film of an amorphousalloy of Tb-Fe series to which a third metal has been added.Magnetooptical recording media of Tb-Co series and Tb-Fe-Co series areknown as well.

Though the magnetooptical recording media comprising a thin film of anamorphous alloy as exemplified above have excellent recording andreproducing characteristics, they still involve such a serious problemfrom a practical standpoint that the amorphous alloy thin film issubject to oxidation in the course of ordinary use and thecharacteristics come to change with time.

The mechanism of oxidative deterioration of amorphous alloy thin filmscomprising transition metals and rare earth elements as mentioned above,is discussed, for example, in Journal of the Society of AppliedMagnetism of Japan, Vol. 9, No. 2, pp 93-96, and this paper reports thatthis mechanism of oxidative deterioration may be classified into threetypes as noted below.

(a) Pit corrosion

By pit corrosion is meant the occurrence of pinholes in the amorphousalloy film. This corrosion proceeds mainly under the circumstances ofhigh humidity, and it markedly proceeds, for example, in films of Tb-Feand Tb-Co series.

(b) Surface oxidation

A surface oxide layer is formed on the surface of the amorphous alloyfilm, whereby the Kerr-rotation angle θk of the film changes with timeand eventually comes to decrease.

(c) Selective oxidation of rare earth element

Rare earth elements present in magnetooptical recording films areselectively oxidized, whereby coercive force Hc of the films comes tolargely change with time.

Various attempts have heretofore been made to inhibit such oxidativedeterioration of amorphous alloy thin films as mentioned above. Forinstance, there is proposed a procedure in which a thin film of anamorphous alloy is to have a three-layer structure wherein the film issandwiched between anti-oxidizing protective layers such as those of Si₃N₄, SiO, SiO₂, and AIN. The anti-oxidizing protective layers as proposedabove, however, involved such problems that they are relativelyexpensive and, at the same, time, they require much time and labor to beformed on amorphous alloy thin films, and that a sufficient inhibitionof oxidative deteroration of the films is not always expected even whensuch anti-oxidizing protective layers are formed on the films.

Furthermore, various attempts are being made to improve resistance tooxidation of amorphous alloy thin films by incorporating a thirdcomponent metal into the films such as Tb-Fe and Tb-Co series.

For instance, Journal of the Society of Applied Magnetism of Japan citedabove discloses an attempt to improve resistance to oxidation ofamorphous alloy thin film of Tb-Fe or Tb-Co series by incorporation intothe films of such third component metal as Co, Ni, Pt, Al, Cr and Ti inan amount of up to 3.5 atom %. In connection with the attempt, the saidJournal reports that the incorporation of small amounts of Co, Ni and Ptinto Tb-Fe or Tb-Co is effective in inhibiting the surface oxidation andhole corrosion of the resulting film but has not effect on inhibition ofthe selective oxidation of Tb contained as a rare earth element in thisfilm. This disclosure means that when small amounts of Co, Ni and Pt areadded to Tb-Fe or Tb-Co, Tb present in the resulting film is selectivelyoxidized, and coercive force Hc of the film largely changes. Thus, evenwhen small amounts up to 3.5 atom % of Co, Ni and Pt are added to Tb-Feor Tb-Co, no sufficient improvement in resistance to oxidation of theresulting film is made.

With the view of improving resistance to oxidation of amorphous alloythin films, a teaching on the amorphous alloy thin films which areobtained by adding Pt, Al, Cr and/or Ti in an amount up to 10 atom % toTb-Fe or Tb-Fe-Co is disclosed on page 209 of the Proceedings of TheNineth Conference the Society Applied Magnetism of Japan (Nov. 1985).Even when Pt, Al, Cr and /or Ti in an amount up to 10 atom % are addedto Tb-Fe or Tb-Fe-Co, however, inhibition of selective oxidation of Tbpresent in the resulting films is not sufficient, though the surfaceoxidation and hole corrosion can be inhibited to a fairly effectiveextent. Thus, there was still left such a problem that coercive force Hcof the resultant films will largely change with time, and eventually thecoercive force Hc will largely decrease.

The prior art references discussed above do not disclose a thin film ofan amorphous alloy as disclosed herein.

Journal of Magnetism & Magnetic Materials, 41, (1984), pp 128-130 and pp125-127 discloses amorphous alloys of Fe-B series having added theretoup to about 3 atom % of Co, Cr or Pt. The amorphous alloys are formedinto ribbons having a thickness of from 25 to 30 μm, and their magneticstrains are studied. None of the disclosed alloys has, however, asufficiently improved resistance to oxidation.

Furthermore, amorphous alloy ribbons obtained by a melt spinning orsplat cooling method as described in this paper are magnetizable withinthe ribbon plane rather than perpendicularly to the ribbon plane. Noconsideration is given as to possibility of vertical magnetization ofthe ribbons.

Japanese Patent Laid-Open Publication 58-7806 discloses polycrystallinethin films having a composition of PtCo in which Pt is contained in anamount of 10-30 atom %.

However, the polycrystalline thin films having this composition of PtCoinvolves such problems that the polycrystalline thin films as formedrequire heat treatment such as annealing because that arepolycrystalline, that grain boundaries sometimes appear as noisesignals, and that the polycrystalline thin films are high in Curiepoint.

OBJECT OF THE INVENTION

The invention is to solve the above-discussed problems associated withthe prior art and an object of the invention is to provide a thin filmof an amorphous alloy which has excellent magnetooptical characteristicsincluding increased coercive force and large Kerr-and Faraday-rotationangles, and which is excellent in resistance to oxidation and inconsequence the coercive force and Kerr-angle of the film do notsubstantially change with time, and which has a high reflectance.

SUMMARY OF THE INVENTION

A thin film of an amorphous alloy according to the invention comprises:

(i) at least one element selected from Fe and Co,

(ii) at least one element selected from Pt and Pd, and

(iii) at least one element selected from

(a) 3d transition elements other than Fe and Co,

(b) 4d transition elements other than Pd,

(c) 5d transition elements other than Pt,

(d) light rare earth elements, (i.e. La, Ce, Pr, Nd, Pm, Sm and Eu)

(e) Group III B elements,

(f) Group IV B elements,

(g) Group V B elements, and

(h) Group VI B elements,

and has an easy axis of magnetization perpendicular to the film face.

The thin film of an amorphous alloy according to the invention hasexcellent magnetooptical characteristics including increase coerciveforce and large Kerr-rotation angle and Faraday-rotation angle. Further,it is excellent in resistance to oxidation, and in consequence, thecoercive force and Kerr-angle of the film do not substantially changewith time. In addition, it has a high reflectance, and in turn excellentreproducing characteristics such as increased S/N ratio.

DETAILED DESCRIPTION OF THE INVENTION

The thin film of an amorphous alloy according to the invention will nowbe described in detail.

The thin film of an amorphous alloy according to the invention comprises(i) at least one element selected from Fe and Co, (ii) at least oneelement selected from Pt and Pd and (iii) at least one element selectedform the group (a), (b), (c), (d), (e), (f), (g) and (h) as noted belowand has and easy axis of magnetization perpendicular to the film face.

(i) at least one element selected from Fe and Co

Fe and/or Co is contained in the amorphous alloy thin film according tothe invention preferably in an amount of from 2 to 95 atom %. In caseswhere a half or more (at least 50 atom %) of the element or elements(iii) contained in the film comprises a light rare earth element orelements, it is preferable that the film contains Fe and/or Co in anamount of from 5 to 84 atom %, in particular from 10 75 atom %. In caseswhere a half or more (at least 50 atom %) of the element or elements(iii) contained in the film comprises an element or elements other thanlight rare earth elements, Fe and/or Co is contained in the film in anamount of preferably from 5 to 94 atom %, more preferably from 10 to 89atom %, and most preferably from 10 to 80 atom %.

(ii) at least one element selected from Pt and Pd

It is sufficient that the film contains more than 0 atom % of Pt and/orPd. Preferably the film contains up to 94 atom % of Pt and/or Pd. Incases where a half or more (at least 50 atom %) of the element orelements (iii) contained in the film comprises a light rare earthelement or elements, it is preferable that the film contains Pt and/orPd in an amount of from 5 to 94 atom %, in particular from 10 to 80 atom%. In cases where a half or more (at least 50 atom %) of the element orelements (iii) contained in the film comprises an element or elementsother than light rare earth elements, Pt and/or Pd is contained int hefilm in an amount of preferably for up to 90 atom %, more preferably upto 80 atom %, and most preferably from 10 to 80 atom %.

The presence of Pt and/or Pd in the film brings about the followingadvantages.

(1) In cases where films contain light rare earth element(s).

It is possible to make films vertically magnetizable without using anyheavy rare earth elements, which have heretofore been necessary toprepare vertically magnetizable films. The films are resistant to pitcorrosion and surface oxidation, and the Kerr-angle does not change withtime. Especially, in cases wherein the films contain at least 5 atom %of Pt and/or Pd, selective oxidation of light rare earth element presentin the films is inhibited whereby the coercive force does not changewith time and the reflectance on the film face is enhanced.

(2) In cases where films do not contain light rare earth element(s).

Amorphous, vertically magnetizable films which are resistant to pitcorrosion and surface oxidation, and whose Kerr-angle does not changewith time can be provided. Especially, in cases where the films containat least 5 atom % of Pt and/or Pd, the reflectance is enhanced.

(iii) at least one element selected from the groups (a), through (h).

The thin film of an amorphous alloy according to the inventioncomprises, in addition to (i) and (ii) above, at least one elementselected from the group (a) through (h) noted below.

(a) 3d transition elements other than Fe and Co

Examples of 3d transition elements other than Fe and Co include Sc, Ti,V, Cr, Mn, Ni, Cu and Zn. Of these, Ti, Ni, Cu and Zn are preferred.

(b) 4d transition elements other than Pd

Examples of 4d transition elements other than Pd include Y, Zr, Nb, Mo,Tc, Ru, Rh, Ag and Cd. Of these, Zr and Nb are preferred.

(c) 5d transition elements other than Pt

Examples of 5d transition elements other than Pt include Hf, Ta, W, Re,Os, Ir, Au and Hg. Of these, Ta is preferred.

(d) Light rare earth elements (i.e. La, Ce, Pr, Nd, Pm, Sm and Eu)

Of these, Nd is preferred.

(e) Group III B elements

Examples of Group III B elements include B, Al, Ga, In and Tl. Of these,B, Al and Ga are preferred.

(f) Group IV B elements

Examples of Group IV B elements include C, Si, Ge, Sn and Pb. Of theseSi, Sn, Pb and Ge are preferred.

(g) Group V B elements

Examples of Group V B elements include N, P, As, Sb and Bi. Of these, Sbis preferred.

(h) Group VI B elements

Examples of Group VI B elements include S, Se, Te, and Po. Of these Teis preferred.

At least one element selected from the groups (a) through (h) iscontained in the amorphous alloy thin film according to the inventionpreferably in an amount of from 2 to 95 atom %. In cases where a half ormore (at least 50 atom %) of the element or elements (iii) contained inthe film comprises a light rare earth element or elements, it ispreferable that the film contains the element or elements (iii) in anamount of from 1 to 80 atom %, more preferably from 10 to 70 atom %, andin particular from 10 to 50 atom %. In cases where a half or more (atleast 50 atom %) of the element or elements (iii) contained in the filmcomprises an element or element other than light rare earth elements,the element or elements (iii) are contained in the film in an amount ofpreferably from 5 to 94 atom %, more preferably form 10 to 89 atom %,and most preferably from 10 to 80 atom %.

The thin film having the composition mentioned above is an amorphousalloy with an easy axis of magnetization perpendicular to the film faceas confirmed by broad angle X-ray diffractmetory and may exhibit aKerr-hysterisis loop of a favorable square-shaped form.

By the expression "the film exhibits a Kerr-hysterisis loop of afavorable square-shaped form" is meant that the ratio θk₂ /θk₁ is atleast 0.8 wherein θk₁ is a Kerr-rotation angle at saturationmagnetization where the external magnetic field is maximum and θk₂ is aKerr-rotation angle at remanent magnetization where the externalmagnetic field is zero.

As described above, the films containing at least 15 atom % of Pt and/orPd have an improved reflectance R when compared with films containing noPt or Pd. When amorphous alloy thin films are utilized in magnetoopticalrecording, it is not necessary to consider medium noise owing to grainboundaries because of the amorphous nature of the medium. Shot noise ofthe optical detector employed must be considered. In this case it willbe appreciated that since S/N is proportional to Rθk, it is sufficientto enlarge at least one of R and θk in order to enhance the S/N.Accordingly, the fact that the amorphous alloy films may have anincreased reflectance R is advantageous, since it leads to an enhancedS/N in magnetooptical recording.

In the present invention, it is also possible to improve the Curiepoint, compensation temperature, coercive force Hc or Kerr-rotationangle θk of the film, or to reduce the cost of production byincorporation various elements into the film. These elements for thepurposes intended may be used, for example, in such a proportion thatthey substitute for less than 50 atom % of the element or elements(iii). Examples of such other elements are heavy rare earth elements,including, for example, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. When theseheavy rare earth elements are conjointly used, at least 5 atom % of Ptand/or Pd should preferably be used to overcome the problem of selectiveoxidation.

A process for preparing the amorphous alloy thin films of the presentinvention is illustrated hereinafter.

The amorphous alloy thin films according to the invention may beprepared by depositing a thin film having a predetermined composition ona substrate, wherein the substrate is maintained at about roomtemperature, and a composite target with chips of elements constitutingthe desired film in the predetermined proportions thereon or an alloytarget having the predetermined composition is deposited by thesputtering method or electron beam evaporation method on said substrate(this substrate may be fixed, or may rotate on its axis or may rotate onits axis while revolving).

Thus, the amorphous alloy thin films according to the invention may beformed at room temperature, and the films so formed are not always inneed of such heat treatment as annealing that is usually required forallowing the films to have an easy axis of magnetization perpendicularin the film.

If necessary, in this connection, the amorphous alloy thin filmaccording to the invention can also be formed on a substrate whileheating the substrate to 50°-600° C., or while cooling the substrate to-50° C.

At the time of sputtering, moreover, biasing a substrate is alsopossible so that the substrate comes to have a negative potential. Bydoing so, ions of an inert gas such as argon accelerated in the electricfield will hit not only target substances but also the film being formedand consequently a vertically magnetizable film having excellentcharacteristics may be obtained.

The thickness of the amorphous alloy thin films according to theinvention can be from 20 to 50000 Å, preferably from 100 to 5000 Å.

Since the amorphous alloy thin films according to the invention have aneasy axis of magnetization perpendicular to the film face, they areutilizable in such various fields as magnetic recording materialsincluding vertical magnetic recording films, magnetic bubble memoriesand magnetooptical recording films, and in optical modulaters whichutilize magnetooptical effects.

In the field of vertical magnetic recording, the amorphous alloy thinfilms according to the invention find application as recording films ofvertical flexible discs and rigid magnetic discs. In the field ofmagnetooptical recording, magnetooptical discs, magnetooptical cards andmagnetooptical tapes for recording and reproducing information signals,or stationary or moving images utilizing the Kerr-rotation angle orFaraday-rotation angle of the films. Further, they may be used inoptical modulators which control the Kerr-or Faraday-rotation angle ofan installed amorphous alloy thin film by controlling the externalmagnetic field, and operate a photo cell by changing a photo quantity ofa relection or transmission light.

The case where the amorphous alloy thin films according to the inventionare as recording films of magnetooptical discs is illustratedhereinafter.

The films according to the invention are vertically magnetizable filmswith an easy axis of magnetization perpendicular to the film and,preferred films have the Kerr hysterisis loop of a square-shaped form,that is θk under the circumstances where no external magnetic fieldexists is practically the same as θk at saturation magnetization wherethe external magnetic field is maximum, and also the coercive force Hcis large, and hence they are suitable as magnetooptical recording films.Furthermore, that θk is favorable means that θf is also favorable, andaccordingly the amorphous alloy thin films according to the inventionare utilizable in both of Kerr-effect utilization system and Faradayeffect utilization system.

Furthermore, since the films according to the invention are excellent inresistance to oxidation, they are not always in need of use of suchprotective films for prevention of oxidation as used in the conventionalfilms comprising heavy rare earth elements and 3d transition metalalloys such as Tb-Fe. Tb-Fe-CO.

Moreover, it is not always necessary to use antioxidizing materials in asubstrate adjacent to the recording film or other functional films (e.g.enhancing film and reflection film), or adhesive layers for laminationpurposes.

Further, even when enhancing film and/or reflection film is formed onthe amorphous alloy films according to the invention, the films can beformed by the wet film forming method such as the spin or spray coatingprocess that could not be employed in the conventional magnetoopticalrecording films, in addition to the dry film forming method such asvacuum evaporation or sputtering.

Accordingly, the structure of magnetooptical discs bearing the amorphousalloy films according to the invention recording films thereon mayinclude such structure as mentioned below.

(i) Substrate/recording film,

(ii) Substrate/enhancing film/recording film,

(iii) Substrate/recording film/reflection film,

(iv) Substrate/enhancing film/recording film/reflection film, and

(v) Substrate/enhancing film/recording film/enhancing film/reflectionfilm.

The magnetooptical discs having such structures illustrated above mayalso have on the outermost layer of the recording film side a protectivefilm or protective label for imparting scratch resistance or resistanceto oxidation to said outermost layer.

The enhancing films may be of organic or inorganic materials so long asthey have a refractive index larger than that of a substrate.

Examples of suitable materials for enhancing films include, for example,oxides such as TiO₂, TiO, ZnO, ITO (indium tin oxide), ZrO₂, Ta₂ O₅, Nb₂O₅, CeO₂, SnO₂ and TeO₂ ; nitrides such as Si₃ N₄, AlN and BN; sulfidessuch as ZnS and CdS; and ZnSe, SiC and Si. Further, transparentmaterials having Faraday effect such as ferrites, typically cobaltferrite, and garnet, may also be used as a material for materials forenhancing films.

As the substrate, there may be used inorganic material such as glass,aluminum, etc. and organic material such as polymethyl methacrylate,polycarbonate, polymer alloy of polycarbonate and polystyrene, amorphouspolyolefins as disclosed in U.S. Pat. No. 4,614,778,poly-4-methyl-1-pentene, epoxy resin, polyether sulfone, polysulfone,polyether imide, etc.

Further, the structure of the magnetooptical discs is not limited onlyto the structure (i)-(v) mentioned above, and the discs may be providedwith a subbing layer, anti-oxidizing film or highly permeable softmagnetic film, if necessary, and the discs may be used either singly orin the form of a laminated disc obtained by bonding two discs eachother.

EFFECT OF THE INVENTION

A thin film of an amorphous alloy according to the invention comprising(i) at least one element selected from Fe and Co, (ii) at least oneelement selected from Pt and Pd and (iii) at least one element selectedform the groups (a) to (h) as mentioned above, and having an easy axisof magnetization perpendicular to the film face, has excellentmagnetooptical characteristics including increased coercive force andlarge Kerr-rotation angle and Faraday-rotation angles, and is excellentin resistance to oxidation and in consequence the coercive force andKerr-rotation angle of the film do not substantially change with time.The film has a high reflectance as well. Further, the amorphous alloythin film according to the invention may be formed on a substrate atroom temperature, and the film so formed need not be heat treated.

The invention will be further illustrated by the following.

EXPERIMENT RUNS 1-21

Using a composite target with chips of Pt and another element arrangedin predetermined proportions on Co target, there was deposited on aglass substrate at 20°-30° C. by DC magnetron sputtering an amorphousalloy thin film having the composition as denoted in Table 1. Theconditions under which the film was formed included Ar pressure of 5mTorr., Ar flow rate of 3 sccm and ultimate degree of vacuum of not morethan 5×10⁻⁶ Torr, and a DC current value (A) and a sputter time (sec)were shown in Table 1.

The crystalline condition of the films obtained was determined by broadangle X-ray diffractometry. The composition of the films obtained wasdetermined by ICP emission spectroscopic analysis.

The Kerr-rotation angle was measured by the inclination incidence method(λ=633nm) at a remanent magnetization on the external magnetic field ofzero from the side of the glass substrate. A concrete method ofmeasurement and apparatus therefor to be employed in the inclinationincident method are described in "Measuring Techniques of MagneticMaterials", compiled by Kazuo Yamakawa (published by Torikepps K. K. onDec. 15, 1985), pp. 261-263.

The reflection of the films obtained was determined with λ=780nm, usingan Al film formed on a glass substrate by vacuum evaporation as astandard sample.

Further, the alloy films obtained were tested for the resistance tooxidation in the manner as noted below. The film as formed on the glasssubstrate was subjected to an environment test in which the films isallowed to stand under a hot humid condition of 85° C., and 85% RH for aperiod of 240, 450 or 1000 hours. At the end of the period, theKerr-rotation angle (θk), reflectance (R) and coercive force (Hc) weredetermined and compared with the initial values prior to the environmenttest, θk₀,R₀ and Hc₀, respectively. The results are shown in Table 1.

EXPERIMENT RUNS 22 and 23

A thin film of an alloy of Pt-Co or Tb-Co was prepared and testedfollowing the procedure of the preceding Experiment Runs expect that acomposite target with a chip of Pt or Tb arranged on a Co target wasused. The results are shown in Table 1. T,0240

EXPERIMENT RUN 24

Using a composite target with chips of Pd, Nd and Co arranged on a Cotarget, a thin film of an alloy of Pd-Nd-Co series was formed on a glasssubstrate by a DC magnetron sputtering method. The conditions underwhich the film was formed included Ar pressure of 5m Torr., Ar flow rateof 3 sccm, ultimate degree of vacuum of not more than 5×10⁻⁶ Torr., DCcurrent of 0.20 A, and sputter time of 90 seconds. It was revealed by abroad angle X-ray diffractometry that the film obtained was amorphous,and it was also revealed by a fact that a Kerr-rotation angle wasobserved that the film was vertically magnetizable.

EXPERIMENT RUN 25

Using a composite target with chips of Sb and Pd arranged on a Cotarget, a thin film of an alloy of Pd-Sb-Co series was formed on a glasssubstrate by a DC magnetron sputtering method. The conditions underwhich the film was formed included Ar pressure of 5m Torr., Ar flow rateof 3 sccm, ultimate degree of vacuum of not more than 5×10⁻⁶ Torr., DCcurrent of 0.20 A, and sputter time of 90 seconds. It was revealed by abroad angle X-ray diffractometry that the film obtained was amorphous,and it was also revealed by a fact that a A Kerr-rotation angle wasobserved that the film was vertically magnetizable.

What is claimed is:
 1. A thin film of an amorphous alloy consistingessentially of(i) 2 to 95 atom % of at least one element selected fromFe and Co, (ii) at least 15 atom % to 94 atom % of at least one elementselected form Pt and Pd, and (iii) 2 to 95 atom % of at least oneelement selected from(a) 3d transition elements other than Fe and Co,(b) 4d transition elements other than Pd, (c) 5d transition elementsother than Pt, (d) La, Ce, Pr, Nd, Pm, Sm, Eu or mixtures thereof, (e)Group III B elements, (f) Group IV B elements, (g) Group V B elements,and (h) Group VI B elements,and said film having an easy axis ofmagnetization perpendicular to its face.
 2. The thin film of amorphousalloy in accordance with claim 1 wherein when a transition elementsother than Fe and Co is present, it is selected from the groupconsisting of Ti, Ni, Cu or Zn.
 3. The thin film of an amorphous alloyin accordance with claim 1 wherein when a 4d transition elements otherthan Pd are Zr or Nb.
 4. The thin film of an amorphous alloy inaccordance with claim 1 wherein when a 5d transition elements other thanPt is present, said element is Ta.
 5. The thin film of an amorphousalloy in accordance with claim 1 wherein when an element selected fromLa, Ce, Pr, Nd, Pm, Sm and Eu is present, it is selected from the groupconsisting of Nd, Sm or Pr.
 6. The thin film of an amorphous alloy inaccordance with claim 1 wherein when a Group III B element is present,it is selected from the group consisting of B, Al or Ga.
 7. The thinfilm of an amorphous alloy in accordance with claim 1 wherein when aGroup IV B element is present, it is selected from the group consistingof Si, Sn, or Pb.
 8. The thin film of an amorphous alloy in accordancewith claim 1 wherein when a Group V B element is present, said elementis Sb.
 9. The thin film of an amorphous alloy in accordance with claim 1wherein when a Group VI B element is present, said element is Te. 10.The thin film of an amorphous alloy in accordance with any one of thepreceding claims 1 to 9 wherein said film has a thickness of from 20 to50000 Å.
 11. The thin film of an amorphous alloy in accordance withclaim 1 wherein (iii) is at least one element selected from 3dtransition elements other than Fe and Co.
 12. The thin film of anamorphous alloy in accordance with claim 1 wherein (iii) is at least oneelement selected from 4d transition elements other than Pd.
 13. The thinfilm of an amorphous alloy in accordance with claim 1 wherein (iii) isat least one element selected from 5d transition elements other than Pt.14. The thin film of an amorphous alloy in accordance with claim 1wherein (iii) is at least one element selected from La, Ce, Pr, Nd, Pm,Sm and Eu.
 15. The thin film of an amorphous alloy in accordance withclaim 1 wherein (iii) is at least one element selected from Group III Belements.
 16. The thin film of an amorphous alloy in accordance withclaim 1 wherein (iii) is at least one element selected form Group IV Belements.
 17. The thin film of an amorphous alloy in accordance withclaim 1 wherein (iii) is at least one element selected from Group V Belements.
 18. The thin film of an amorphous alloy in accordance withclaim 1 wherein (iii) is at least one element selected from Group VI Belements.
 19. The thin film of an amorphous alloy in accordance withclaim 1 wherein when at least 50 atom % of (iii) is selected from La,Ce, Pr, Nd, Pm, Sm, Eu and mixtures thereof, (i) is present in said filmin an amount of 5 to 84 atom %; and when at least 50 atom % of (iii) isother than an element selected from La, Ce, Pr, Nd, Pm, Sm, Eu andmixtures thereof, (i) is present in said film in an amount of 5 to 94atom %.
 20. The thin film of an amorphous alloy in accordance with claim1 wherein when at least 50 atom % of (iii) is selected form La, Ce, Pr,Nd, Pm, Sm, Eu and mixtures thereof, (ii) is present in said film in anamount of 15 to 94 atom %; and when at least 50 atom % of (iii) is otherthan an element selected from La, Ce, Pr, Nd, Pm, Sm, Eu and mixturesthereof, (ii) is present in said film in an amount of 15 to 90 atom %.21. The thin film of an amorphous alloy in accordance with claim 1wherein when at least 50 atom % of (iii) is selected from La, Ce, Pr,Nd, Pm, Sm, Eu and mixtures thereof, (iii) is present in said film in anamount of 10 to 80 atom %; and when at least 50 atom % of (iii) is otherthan an element selected from La, Ce, Pr, Nd, Pm, Sm, Eu and mixturesthereof, (iii) is present in said film in an amount of 5 to 94 atom %.